{
  "id": "evt_3f9a1c2b4d5e6f7a8b9c0d1e",
  "type": "promptshield:attack:blocked",
  "created": 1705312200,
  "data": { "...": "event-specific payload" }
}

import crypto from 'crypto';
import express from 'express';

const app = express();
const SECRET = process.env.SECUREAI_WEBHOOK_SECRET; // whsec_...
const TOLERANCE_SECONDS = 300;

// Capture the RAW body — do not use express.json() before verifying.
app.post('/webhooks/secureai', express.raw({ type: 'application/json' }), (req, res) => {
  const header = req.get('X-SecureAI-Signature') || '';
  const parts = Object.fromEntries(header.split(',').map(kv => kv.split('=')));
  const t = Number(parts.t);
  const rawBody = req.body.toString('utf8');

  if (!Number.isFinite(t) || Math.abs(Date.now() / 1000 - t) > TOLERANCE_SECONDS) {
    return res.status(400).send('stale or invalid timestamp');
  }

  const expected = crypto.createHmac('sha256', SECRET).update(`${t}.${rawBody}`).digest('hex');
  const ok = parts.v1 &&
    crypto.timingSafeEqual(Buffer.from(parts.v1), Buffer.from(expected));
  if (!ok) return res.status(401).send('bad signature');

  const event = JSON.parse(rawBody);
  console.log('Received', event.type, event.id);
  res.sendStatus(200);
});

import hashlib, hmac, time
from flask import Flask, request, abort

app = Flask(__name__)
SECRET = b"whsec_..."          # your signing secret
TOLERANCE_SECONDS = 300

@app.post("/webhooks/secureai")
def secureai_webhook():
    header = request.headers.get("X-SecureAI-Signature", "")
    parts = dict(kv.split("=", 1) for kv in header.split(","))
    t = int(parts.get("t", "0"))
    raw_body = request.get_data()  # raw bytes — do NOT use request.json first

    if abs(time.time() - t) > TOLERANCE_SECONDS:
        abort(400, "stale timestamp")

    signed = f"{t}.".encode() + raw_body
    expected = hmac.new(SECRET, signed, hashlib.sha256).hexdigest()
    if not hmac.compare_digest(parts.get("v1", ""), expected):
        abort(401, "bad signature")

    return "", 200